import 'package:flutter/material.dart';

void main() {
  runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: const Text("你好flutter"),
        ),
        body: const MyApp(),
      ),
    ),
  );
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.red,
      height: 200,
      width: 200,
      alignment: Alignment.topLeft,
      child: Container(
        height: 100,
        width: 100,
        color: Colors.blue,
      ),
    );
  }
}
